I am sure I am not the only product manager who has been asked the question: “What is the difference between Product Manager and Project Manager?”. I think the most important difference is the level of involvement of both these positions throughout the product life cycle.
The Product Manager is involved from product conception all the way till the product is obsolete and retired. The Project Manager is involved in the planning of a project (development of product) till the product is launched. The Product Manager is tasked to create value for a product from cradle to grave, whereas a Project Manager is tasked to plan and execute a development project with the appropriate resources, budget and deadline. The level of involvement is deeper for Project Manager during the development phase, but the overall life cycle of the product is handled by the Product Manager.
This article refers to the Project Manager as “Vertical leadership” and the Product Manager as “Horizontal leadership”. I think there is some truth in this definition, though the level of involvement of a Product Manager can also be quite deep and it really depends on the type of development. For new product categories, I believe the Product Manager has to provide guidance and could very well be deeply involved in many decisions which are not part of the Project Manager’s job.